Disciplines / Research questions
Physics
691 research topics · 2739 questions
Alternative Way of Solving the Ice-Type Models6 questions
Integrable manifolds and commuting transfer matrices of the odd eight-vertex model
Open for about 8 yearsExtending the FPRAS for the six-vertex model with an unwindable constraint function beyond two-by-two-intersection-free circuit decompositions and the regime
Open for about 4 yearsDeriving Bethe equations for the XYZ spin chain from the matrix-product-operator construction
Open for less than 1 yearAnalytic proof of the even-index Yang–Baxter conjectures for descendants of the six-vertex model from the Drinfeld doubles of dihedral group algebras
Open for about 16 yearsCompleting the approximation-complexity classification of the six-vertex model: the white region of the disordered phase and the Tutte point on planar graphs
Open for about 8 yearsCompleteness of the homogeneous – Bethe ansatz for the eight-vertex model with quasi-periodic boundary conditions on an odd number of sites
Open for about 11 years
analytic Bethe Ansatz2 questions
Completeness of the Wronskian Bethe ansatz for rational gl(m|n) spin chains in arbitrary highest-weight representations and the exceptional specialisation locus
Open for about 6 yearsCompleting the analytical Bethe ansatz for gl(M|N) super-spin chains: the M=N case, non-commuting boundary matrices, and reflection-superalgebra representations
Open for about 19 years
Andrews–Baxter–Forrester model3 questions
Bosonic finitized character formulas and the CTM recursion for the one-dimensional sums of the fused RSOS models with
Massive integrable structure of the off-critical logarithmic minimal models LM(p,p';t)
Complete analysis of the open off-critical RSOS quantum chains: integrable boundaries, open-chain spectra, and reality of the non-Hermitian double-row transfer matrices
ASEP/TASEP2 questions
Ashkin–Teller model3 questions
Completing the exact solution of the Ashkin–Teller conformal field theory: the 4-state Potts point, degenerate conformal blocks at rational central charge, and continuation to generic central charge
The conjecture for Ashkin–Teller parafermionic interfaces and its Schramm-formula test
Microscopic-to-conformal boundary dictionary of the critical quantum Ashkin–Teller chain: non-universal coupling maps, semi-duality-protected level crossing, and four-state Potts asymptotics
Ashkin–Teller self-dual line1 questions
ballistic transport2 questions
Open extensions of ballistic macroscopic fluctuation theory for the hard-rod gas: slowly varying external potentials, mesoscopic fluctuating hydrodynamics from inhomogeneous states, and the Toda chain
Theory of finite-size validity of integrable hydrodynamics: why very small Toda chains reproduce thermodynamic ballistic correlation profiles
basic hypergeometric functions1 questions
Baxter operator4 questions
Rigorous foundations of Baxter's relation for the generic periodic XYZ spin chain: the parameter , completeness, singular solutions, and Bethe vectors
Open for about 54 yearsAlgebraic completion of the Q-operator programme for the XXZ chain at roots of unity: FM-string creation operators, the hidden Onsager-type symmetry, Bethe completeness, and FM-string thermodynamics
Open for about 5 yearsRigorous QQ-system foundation for spin chains: operator-level proofs for general representations, Wronskian Bethe completeness, and a Baxter analogue
Open for about 6 yearsPolynomiality and commutativity of the Q-operator for the open XXZ spin chain with diagonal boundaries (Vlaar-Weston Conjecture 6.3)
Open for about 6 years
Bazhanov–Baxter three-dimensional lattice model2 questions
Bethe wave function3 questions
Ab initio derivation of generalised hydrodynamics from Bethe wave functions: controlling the sum over permutations in the hydrodynamic limit
Open for about 3 yearsDomain of validity of the effective Bethe ansatz for non-integrable spin chains: optimal off-shell states and cost functions, the mechanism of factorized-scattering breakdown, and real-time dynamics
Open for less than 1 yearProof of the Kotousov–Lukyanov conjectures for the scaling-limit norms of Bethe states in the critical XXZ Heisenberg chain
Open for about 7 years
Bethe equations3 questions
Weak string hypothesis for gl(n|m) supersymmetric spin chains: rigorous foundation
Open for about 15 yearsCompleting the exact solution of the Izergin-Korepin Gaudin model: Bethe-root structure, eigenstates, and completeness
Open for about 1 yearPhysicality of singular Bethe solutions in the remaining open cases: sufficiency for the higher-spin XXZ chain and eigenstate construction for strange repeated-root solutions
Open for about 11 years
Completeness of Bethe equations3 questions
Completeness of the Bethe equations for the periodic spin-1/2 XXX Heisenberg chain: proving the counting conjecture
Open for about 13 yearsCompleteness and soundness of the off-diagonal Bethe ansatz solution of anisotropic spin-1/2 chains with arbitrary boundary fields: the open XYZ chain
Open for about 13 yearsCompleteness of the coordinate Bethe ansatz for the periodic ASEP with tunable interaction (the general-U Bethe equations of Nakerst–Prosen–Haque)
Open for about 2 years
Bethe lattice magnetization, free energy, and critical behavior2 questions
Low-temperature critical exponents of the Ising model on random trees and locally tree-like random graphs: the susceptibility exponent and the specific-heat exponent
Open for about 13 yearsRigorous organization of Bethe states and effective evaluation of the Bethe variational formula for spin systems on the Bethe lattice
Open for about 8 years
Bethe lattice recursion relations2 questions
Invisible-state transmutation thresholds for the q = 3 and q = 4 Potts models beyond mean field: planar random graphs and two-dimensional lattices
Open for about 13 yearsPhase diagram of semiflexible self-avoiding trails with independent crossing and collision weights on the square lattice
Open for about 9 years
Bethe lattice and Cayley tree3 questions
The infinite-dimensional limit of KPZ surface growth and the upper critical dimension of the KPZ universality class
Open for about 40 yearsInvariant sets of the period-two splitting map and the complete catalogue of periodic Gibbs measures for the q-state Potts model on the Cayley tree
Open for about 13 yearsClassification of weakly periodic Gibbs measures for the two-state hard-core model on Cayley trees: exact multiplicity, extremality, and the (k, i, lambda) phase diagram for normal divisors of index four
Open for about 12 years
Bethe root density and hole density3 questions
Even-length Bethe strings and the antiferromagnetic vacuum of the all-loop su(2) Bethe equations in planar N=4 supersymmetric Yang-Mills theory
Thermodynamic root-density equation for the two-parameter Lieb–Liniger/Cheon–Shigehara interpolation beyond the non-interacting line
Edge-region 2-string deviations, special-object numerics, and counting integers in the excited-state nonlinear integral equations of the spin-1 XXZ chain
Bethe roots and complex root structure1 questions
Bethe state norm4 questions
Explicit finite-size normalization of nested Bethe ansatz eigenfunctions for continuum multicomponent quantum gases
Open for about 1 yearRigorous justification of the replica coordinate Bethe ansatz for the log-gamma polymer: Bethe-string norms, completeness, and analytic continuation in replica number
Open for about 12 yearsNorms of Bethe states in the Jaynes-Cummings-Gaudin model: the separated-variable integral versus the Gaudin determinant
Open for about 19 yearsProve or refute the Gaudin-type determinant norm formula for Bethe eigenstates of the hard-wall Lieb-Liniger model
Open for about 3 years
Bethe Ansatz for stochastic processes3 questions
Degenerate spectral biorthogonality for string specializations of the q-Hahn coordinate Bethe eigenfunctions
Determinantal and simplified transition-probability formulas for the multi-species ASEP with long-range jumps, and the integrable two-sided long-range extension
Open problems on the spiked spectral boundary of the ASEP: Bethe-root clustering, restricted-cycle random graphs, and Bethe-ansatz completeness
Bethe strings and string hypothesis2 questions
Validity of the string hypothesis for generalized Hubbard models with nonzero Bethe-equation phases
Open for about 16 yearsUnphysical singular solutions of the periodic spin-1/2 XXX Bethe equations: classification, thermodynamic-limit abundance, and why string-hypothesis counting still works
Open for about 13 years
Bond-dimension extrapolation2 questions
Controlled and scalable variance computation for iPEPS ground states and steady states: cell-size and boundary-dimension requirements, long-distance contraction drift, and direct Liouvillian-norm minimization
Finite bond dimension at two-dimensional quantum criticality in iPEPS: Lifshitz-point convergence, operator content of the truncation geometry, and D as a continuum regulator
bootstrap principle2 questions
Bosonic/fermionic character representation3 questions
Completing the fermionic MLDE classification of two-dimensional fermionic rational conformal field theories and its dictionary to fermionic modular tensor categories
Spinon-type basis and analytic large-k proof of the spinon character formula for graded parafermions ()
Free-fermion realisation of the level- string functions of : Han's Conjectures 2.2 and 2.6 at general rank
boundary matrix3 questions
Quantum integrability of the Coulomb-branch open string: the quantum reflection factor and conserved charges of the D3-brane boundary
Modified boundary crossing for non-invertible symmetries beyond regular module categories: breather spectra, non-regular vacua, and boundary RG flows in 1+1 dimensions
Open problems of the R-matrix bootstrap for the 2d O(N) bosonic model with a boundary
boundary crossing-unitarity4 questions
Boundary crossing relations, dressing factors, bound states, and boundary thermodynamics for integrable open spin chains in AdS3/CFT2
Charge-dependent infinite-dimensional reflection matrices in the sine-Gordon model with a boundary: scalar factors, completeness of defect dressing, and classical boundary correspondence
Completing the exact quantum boundary theory of the complex sine-Gordon model on a half line: reflection CDD factors, boundary-pole classification, and boundary-parameter renormalisation
Genuinely integrable boundaries of the 2d O(N) sigma model: closing the mismatch between conformal (M), Lax (U/kappa), and quantum (BYBE) classifications
boundary entropy1 questions
boundary Yang–Baxter equation3 questions
Completing the boundary scattering theory of massive -perturbed unitary minimal models: the exact – UV–IR map, reflection matrices for general Cardy superpositions, and boundary residual quantum-group symmetry
Classification of solutions of the boundary Yang-Baxter equation beyond the rational quasi-classical case: trigonometric K-matrices and non-quasi-classical (singular) K-matrices
K-matrices for type-II graded Satake diagrams: the graded and twisted reflection-equation conjectures for quantum super-spherical pairs
Braid group representation1 questions
CDD factor3 questions
Open classification of UV completions of integrable -deformed CFTs: admissible CDD factors, remaining spectra, and UV field content
Rigorous convergence of the two-dimensional unitarity iteration and the continuum fate of the CDD fractal
Analyticity, locality and ultraviolet behaviour of fractional-spin CDD deformations of -graded S-matrices
corner environment3 questions
Analytic theory of the corner transfer matrix spectrum and deformed corner Hamiltonian for lattice models on hyperbolic lattices
Direct derivation of the surface–corner scaling function and rigorous proof of the series–CFT identity for the critical Ising rectangle
Completing the corner-operator expansion (COE) of critical profiles near corners: the next nonvanishing apex operators and their amplitudes
corner environment contraction3 questions
Open problems for the reduced-cost corner-transfer contraction of infinite PEPS environments: truncation-error control, criticality limits, symmetry and update-scheme integration, and single-layer benchmarking
Corner-transfer-tensor density-matrix renormalization group for three-dimensional classical lattice models: practical realization and the obstruction behind its failure
Error-controlled tensor-network computation of corner magnetization and corner critical exponents
Corner Transfer Matrices7 questions
Origin of the renormalizability structure of corner-transfer-matrix contractions for the kicked 2D quantum Ising Floquet system and its conjectured entanglement transition
Open for about 10 yearsAsymmetric and three-dimensional extensions of the variational corner transfer matrix renormalization group (vCTMRG)
Open for about 4 yearsEquality of the charge(3) and even constraint capacities on the square lattice, and certified two-sided bounds for these non-local two-dimensional constraints
Open for about 13 yearsRobust contraction of infinite two-dimensional tensor networks with non-Hermitian transfer matrices
Open for about 7 yearsImplicit versus explicit truncation in corner-transfer-matrix and corner-tensor simulation of infinite quantum lattice systems: which truncation style is more accurate per computational cost?
Open for about 14 yearsAnalytic theory of the corner-transfer-matrix spectrum and corner-Hamiltonian renormalization for classical lattice models on hyperbolic lattices at criticality
Open for about 19 yearsLattice-level status of the entanglement-spectrum–corner-Hamiltonian correspondence in integrable open spin chains
Open for about 10 years
Coulomb-gas representation4 questions
Topological lines of the XXZ_q CFT beyond the Coulomb-gas construction: microscopic definition, factorization algebra, modular properties, and embedding into local theories
Coulomb-gas partition functions for multiple SLEs at exceptional parameters: probabilistic, logarithmic-CFT, and lattice interpretation
Free-field resolution and W zero-mode eigenvalue conjectures for minimal models
Completing the regularization of Dotsenko-Fateev integrals: immersed Pochhammer-type cycles, rigorous screened vertex operators for the BPZ minimal models, and the topology of the doubled integration domains
Origin and mechanism of CP violation and its cosmological connection7 questions
Quantitative baryogenesis from the QCD axion's damped, time-varying strong-CP violation: computing the baryon yield coupled to low-scale baryon-number violation across the axion parameter space
Open for about 4 yearsDetermination of the right-handed-neutrino spectrum and the quantitative baryon-asymmetry prediction in the single-CP-phase axion-less solution of the strong CP problem
Open for about 1 yearViability and distinguishability of the linked inflation–spontaneous-CP-violation framework of Hashimoto, Risdianto and Suematsu (2021): multi-field dynamics, quantum-gravity-induced U(1) breaking, and the joint viable parameter space
Open for about 4 yearsQuantitative fate of the internal-time-operator CP violation: can it generate the cosmic baryon asymmetry and the neutrino–antineutrino oscillation asymmetries?
Open for about 4 yearsFirst-principles quantitative viability of electroweak baryogenesis from transient spontaneous CP violation in the 2HDM+a (bubble-wall velocity, dark-matter interplay, and the radiative origin of the CP-breaking phase)
Open for about 4 yearsViability of the strong-CP-guided parity MLRSM: completing the correlated parameter-space map and the parity domain-wall question
Open for about 6 yearsGroup-theoretical CP violation from string theory: UV completion and phenomenological viability of the winding-doublet mechanism
Open for about 8 years
CTM eigenvalues3 questions
Physical origin of flat corner-transfer-matrix spectra and the renormalizability-entanglement connection in 2D strongly coupled Floquet systems
Unusual corrections to the entanglement entropy of the massive XYZ chain and the character structure of its corner transfer matrix
Two-dimensional constraint capacities: the charge(3)-even equality conjecture and certified corner-transfer-matrix bounds